A knock-down-drag-out fight or argument is an extremely angry or violent one — so wild that you can picture people hitting each other to the floor and dragging them.

a knock-down-drag-out fight or argument 一場 knock-down-drag-out 的打架或吵架 is an extremely angry or violent one 是非常兇、非常激烈的那種 — so wild that you can picture people hitting each other to the floor and dragging them 兇到你可以想像有人把對方打倒在地、拖來拖去

It is informal, and it is more American than British, though British readers still understand it.

it is informal 這是口語用法，and it is more American than British 比較偏美式而不是英式，though British readers still understand it 不過英國人還是聽得懂

You will hear it before nouns: a knock-down-drag-out argument, a knock-down-drag-out battle in court or in politics.

before nouns 放在名詞前面 you will hear it 你會聽到這樣用：a knock-down-drag-out argument 一場 knock-down-drag-out 的爭吵，a knock-down-drag-out battle in court or in politics 或法庭、政治上的 knock-down-drag-out 大戰

Though actually, it is often stretched: nobody needs to be dragged along the ground. It can be all words, just very fierce. It is colourful talk, not a polite or legal term.

though actually 不過其實 it is often stretched 這說法常常是誇張的：nobody needs to be dragged along the ground 沒有人真的需要被拖在地上。it can be all words 也可以完全只是用嘴巴吵，just very fierce 只是吵得非常兇而已。it is colourful talk 這是生動的說法，not a polite or legal term 不是有禮貌或法律上的正式用詞

You may also see knockdown-drag-out or knockdown drag-out; the hyphens wander.

knockdown-drag-out or knockdown drag-out 你也可能看到 knockdown-drag-out 或 knockdown drag-out 的寫法；the hyphens wander 連字號的位置並不固定